Oil-glands.–Secretory organs near the root of the tail, probably used in oiling the plumage. Some exhibit tufts of feathers, others are naked.
Operculum (p. [11]).
Pamprodactylous (p. [10]).
Patella.–The knee-cap.
Pouches.–See Air-sacs.
Powder-down patches.–Groups of powder-down feathers (p. [3]).
Praecoces or Nidifugae.–Nestlings which are hatched in a condition that enables them almost immediately to leave the nest and feed themselves.
Primaries or Manuals.–Those wing-quills (Remiges), varying from ten to twelve, borne by the manus or hand. They should properly be counted outwards from the carpus or wrist.
Procnemial.–In front of the knee.
Proximal.–That end of any part or member which is nearest to the imaginary centre or axis of the body.